Vasquez, Alejandra

Abstract Dravet syndrome is a severe developmental and epileptic encephalopathy caused by heterozygous, loss‐of‐function, pathogenic variants in the SCN1A gene. It is characterized by frequent, often prolonged convulsive seizures. Dravet syndrome is associated with diverse comorbid conditions, including developmental impairment, intellectual disability, and behavioral disturbances, in addition to high mortality rates. Prompt diagnosis and treatment initiation are essential to reduce seizure frequency, status epilepticus, and potentially improve neurodevelopmental outcomes. Currently available therapies such as fenfluramine, stiripentol, and cannabidiol have demonstrated significant reduction in convulsive seizure frequency, based on randomized controlled trials and real‐world studies; however, they have not markedly affected non‐seizure symptoms. Emerging therapies such as genetic modulation are promising given their potential for disease modification, seizure frequency reduction, and improvement of non‐seizure outcomes. This review of observational studies and randomized clinical trials provides an overview of the natural history of Dravet syndrome, current treatment guidelines with recently approved medications, addressing both safety and efficacy, and new therapeutic approaches, including disease‐modifying therapies. The therapeutic landscape in Dravet syndrome is evolving, with the use of new antiseizure agents and precision therapies that target the SCN1A variant. Goals of treatment include improvement of seizure burden, neurodevelopment, comorbidities, and quality of life in individuals with Dravet syndrome.

AbstractObjectiveStereoelectroencephalography‐guided radiofrequency thermocoagulation (SEEG‐guided RFTC) has been increasingly used as diagnostic and therapeutic approach for drug‐resistant focal epilepsies (DREs). We aimed to describe seizure outcomes of RFTC before and after further neurosurgical intervention.MethodsRetrospective single‐institution case series of patients who underwent SEEG‐RFTC. The primary outcome was Engel class I–IV classification ([responders Engel I–III and non‐responders Engel IV]) at last follow‐up after RFTC and prior to further neurosurgical intervention (open surgical resection, laser ablation, and neuromodulation).ResultsTwenty‐five patients (median age 18.9 years) with DRE were included. The median follow‐up time after RFTC was 7.2 months, including 20 patients who underwent further intervention (median follow‐up time of 7.3 months) and 5 without intervention (median of 3.5 months). From the patients who had further intervention, 17 (85%) underwent surgical procedure (laser ablation 53%, open surgical resection 47%) (median 4.4 months) and 3 (15%) had responsive neurostimulators placed (median 6.9 months). Prior to further intervention (median follow‐up 3.5 months after RFTC), 12 (48%) patients were classified as responders (12% Engel class I, 16% class II, and 20% class III) and 13 (52%) as non‐responders. Following neurosurgical intervention, 17 (68%) patients were followed for a median time of 2.7 months and 3 were lost to follow‐up. Of eight initial RFTC responders, 87.5% and 12.5% had Engel classes I and III, respectively. Of nine who were non‐responders, 33% had Engel class I, 22% II and III, and 44% IV outcomes following further intervention. No neurologic complications were reported.SignificanceSEEG‐guided RFTC is a well‐tolerated procedure and a beneficial diagnostic approach prior to further neurosurgical interventions in patients with DRE.Plain Language SummarySEEG‐guided RFTC is a well‐tolerated procedure and in the patients who experienced initial seizure reduction (n = 8), subsequent neurosurgical intervention (surgery or neuromodulation) led to favorable seizure outcomes (87.5% seizure freedom and 12.5% worthwhile seizure improvement).

AbstractDevelopmental and epileptic encephalopathies (DEEs) are a group of rare, severe, early-onset epilepsies characterized by pharmacoresistance, marked electroencephalographic abnormalities, and delayed or regressive psychomotor development. DEEs are associated with poor long-term outcomes and increased mortality; however, early recognition and targeted treatment can impact neurodevelopmental outcomes and overall quality of life. Treatment with antiseizure medication is often challenging given drug resistance, chronic polypharmacy, and medication interactions. With advances in genetic testing and increased understanding of the neurobiological mechanisms of DEEs, the treatment approach is evolving and includes repurposed antiseizure medications and targeted therapies, as well as early surgical intervention in select patients. In addition to high seizure burden and neurodevelopmental delay, DEEs are associated with comorbidities affecting a range of body systems; these can include intellectual disability, psychiatric disorders, motor dysfunction, and respiratory and gastrointestinal problems. Over time, these comorbidities increase the complexity of management and have important implications on the disease burden and quality of life for both patients and their caregivers. Multidisciplinary care in DEEs is paramount. We summarize the current evidence on the management of specific DEEs, focusing on targeted therapies and optimizing outcomes.

This commentary is on the original article by Chiron et al on pages 1607–1616 of this issue.

Abstract Objective This study was undertaken to evaluate benzodiazepine (BZD) administration patterns before transitioning to non‐BZD antiseizure medication (ASM) in pediatric patients with refractory convulsive status epilepticus (rSE). Methods This retrospective multicenter study in the United States and Canada used prospectively collected observational data from children admitted with rSE between 2011 and 2020. Outcome variables were the number of BZDs given before the first non‐BZD ASM, and the number of BZDs administered after 30 and 45 min from seizure onset and before escalating to non‐BZD ASM. Results We included 293 patients with a median (interquartile range) age of 3.8 (1.3–9.3) years. Thirty‐six percent received more than two BZDs before escalating, and the later the treatment initiation was after seizure onset, the less likely patients were to receive multiple BZD doses before transitioning (incidence rate ratio [IRR] = .998, 95% confidence interval [CI] = .997–.999 per minute, p = .01). Patients received BZDs beyond 30 and 45 min in 57.3% and 44.0% of cases, respectively. Patients with out‐of‐hospital seizure onset were more likely to receive more doses of BZDs beyond 30 min (IRR = 2.43, 95% CI = 1.73–3.46, p < .0001) and beyond 45 min (IRR = 3.75, 95% CI = 2.40–6.03, p < .0001) compared to patients with in‐hospital seizure onset. Intermittent SE was a risk factor for more BZDs administered beyond 45 min compared to continuous SE (IRR = 1.44, 95% CI = 1.01–2.06, p = .04). Forty‐seven percent of patients ( n = 94) with out‐of‐hospital onset did not receive treatment before hospital arrival. Among patients with out‐of‐hospital onset who received at least two BZDs before hospital arrival ( n = 54), 48.1% received additional BZDs at hospital arrival. Significance Failure to escalate from BZDs to non‐BZD ASMs occurs mainly in out‐of‐hospital rSE onset. Delays in the implementation of medical guidelines may be reduced by initiating treatment before hospital arrival and facilitating a transition to non‐BZD ASMs after two BZD doses during handoffs between prehospital and in‐hospital settings.

AbstractObjectiveThis study was undertaken to describe long‐term clinical and developmental outcomes in pediatric refractory status epilepticus (RSE) and identify factors associated with new neurological deficits after RSE.MethodsWe performed retrospective analyses of prospectively collected observational data from June 2011 to March 2020 on pediatric patients with RSE. We analyzed clinical outcomes from at least 30 days after RSE and, in a subanalysis, we assessed developmental outcomes and evaluated risk factors in previously normally developed patients.ResultsFollow‐up data on outcomes were available in 276 patients (56.5% males). The median (interquartile range [IQR]) follow‐up duration was 1.6 (.9–2.7) years. The in‐hospital mortality rate was 4% (16/403 patients), and 15 (5.4%) patients had died after hospital discharge. One hundred sixty‐six (62.9%) patients had subsequent unprovoked seizures, and 44 (16.9%) patients had a repeated RSE episode. Among 116 patients with normal development before RSE, 42 of 107 (39.3%) patients with available data had new neurological deficits (cognitive, behavioral, or motor). Patients with new deficits had longer median (IQR) electroclinical RSE duration than patients without new deficits (10.3 [2.1–134.5] h vs. 4 [1.6–16] h, p = .011, adjusted odds ratio = 1.003, 95% confidence interval = 1.0008–1.0069, p = .027). The proportion of patients with an unfavorable functional outcome (Glasgow Outcome Scale‐Extended score ≥ 4) was 22 of 90 (24.4%), and they were more likely to have received a continuous infusion.SignificanceAbout one third of patients without prior epilepsy developed recurrent unprovoked seizures after the RSE episode. In previously normally developing patients, 39% presented with new deficits during follow‐up, with longer electroclinical RSE duration as a predictor.

OBJECTIVES: To characterize the pediatric super-refractory status epilepticus population by describing treatment variability in super-refractory status epilepticus patients and comparing relevant clinical characteristics, including outcomes, between super-refractory status epilepticus, and nonsuper-refractory status epilepticus patients. DESIGN: Retrospective cohort study with prospectively collected data between June 2011 and January 2019. SETTING: Seventeen academic hospitals in the United States. PATIENTS: We included patients 1 month to 21 years old presenting with convulsive refractory status epilepticus. We defined super-refractory status epilepticus as continuous or intermittent seizures lasting greater than or equal to 24 hours following initiation of continuous infusion and divided the cohort into super-refractory status epilepticus and nonsuper-refractory status epilepticus groups. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We identified 281 patients (157 males) with a median age of 4.1 years (1.3–9.5 yr), including 31 super-refractory status epilepticus patients. Compared with nonsuper-refractory status epilepticus group, super-refractory status epilepticus patients had delayed initiation of first nonbenzodiazepine-antiseizure medication (149 min [55–491.5 min] vs 62 min [33.3–120.8 min]; p = 0.030) and of continuous infusion (495 min [177.5–1,255 min] vs 150 min [90–318.5 min]; p = 0.003); prolonged seizure duration (120 hr [58–368 hr] vs 3 hr [1.4–5.9 hr]; p < 0.001) and length of ICU stay (17 d [9.5–40 d] vs [1.8–8.8 d]; p < 0.001); more medical complications (18/31 [58.1%] vs 55/250 [22.2%] patients; p < 0.001); lower return to baseline function (7/31 [22.6%] vs 182/250 [73.4%] patients; p < 0.001); and higher mortality (4/31 [12.9%] vs 5/250 [2%]; p = 0.010). Within the super-refractory status epilepticus group, status epilepticus resolution was attained with a single continuous infusion in 15 of 31 patients (48.4%), two in 10 of 31 (32.3%), and three or more in six of 31 (19.4%). Most super-refractory status epilepticus patients (30/31, 96.8%) received midazolam as first choice. About 17 of 31 patients (54.8%) received additional treatments. CONCLUSIONS: Super-refractory status epilepticus patients had delayed initiation of nonbenzodiazepine antiseizure medication treatment, higher number of medical complications and mortality, and lower return to neurologic baseline than nonsuper-refractory status epilepticus patients, although these associations were not adjusted for potential confounders. Treatment approaches following the first continuous infusion were heterogeneous, reflecting limited information to guide clinical decision-making in super-refractory status epilepticus.